This top-performance fleet raises Russia’s air strike and defense capabilities in Syria to the highest standards of any air force in the world, with enough power to take on superior US and Israeli air might in the Syrian arena. The Su-57’s weapon bays are designed to carry Russia’s new nuclear tactical X-50 air-launched cruise missile, although it is not known whether the aircraft in Syria are carrying them.DEBKA Weekly’s military sources see President Vladimir Putin’s decision to send the Su-57 fighters to Syria as substantially raising the big power stakes in Syria after the loss of dozens of Russian troops on Feb. 7 to massive US artillery and air strikes that decimated the Russian, Syrian and pro-Iranian forces crossing the Euphrates River. An American radar-invisible F-22 took part in that raid. The Russians have dubbed the Su-57 the “F-22 killer.”

It is also Russia’s response to Israel’s air offensive on Feb. 10, which targeted the shared Russian-Iranian T-4 air base near Palmyra and smashed four Iranian Revolutionary Guards forward command centers in Syria, after downing an Iranian drone. It is also seen in Moscow as a challenge for Israel’s newly acquired fifth-generation US F-35 combat aircraft.

Does Putin intend to order his mighty airborne strike force to go into battle against the US or Israel in the boiling Syrian arena? If he does, he will be launching the first contest between the most sophisticated warplanes ever devised for a test of superior might between the US and Russia and a war escalation unprecedented, even in Syria.